function s1_hello(){


   echo "hello, world!";
}

function s2_tell_who_i_am(){

   whoami;
}

function s3_which_distro_do_i_use(){

    if [[ -f /etc/os-release ]];then
    source /etc/os-release
    echo "NAME=\"$NAME\""
    elif [[ -f /etc/lsb-release ]];then
    . /etc/lsb-release
    echo "NAME=\"$DISTRIB_ID\""
    else
        cat /etc/issue | head -n 1| sed 's/\\n//g' | sed 's/\\r//g' | sed 's/^\\s*//g'
    fi
}

function s4_view_my_cpu_arch(){

    uname -m;
}

function s5_show_first_scsi_disk_size (){
    lsblk -1 | \grep disk | \grep '^sda' | awk '/^sda/ {sub(/G$/,"",$4); print $4}'
}

function s6_show_main_memory_size_in_megabytes(){

    free -m | grep "Mem:" | awk '{print $2}'


}

#调用函数
#s1_hello
#s2_tell_who_i_am
#s3_which_distro_do_i_use
#s4_view_my_cpu_arch
#s5_show_first_scsi_disk_size
#s6_show_main_memory_size_in_megabytes
